Baize is a coarse woollen (or in cheaper variants cotton) cloth, similar in texture to felt, but more durable.
The surface finish of baize is coarse, thus increasing rolling resistance and perceptibly slowing billiard balls.
Snooker, in which understanding nap effects is part of the game, uses the nappy variety, while pool and carom billiards use the napless type.
For gaming use, baize is traditionally dyed green, in mimicry of a lawn (see Cue sport, "History"), though wide variety of table colours have become accepted.
Bay was similar material to baize, but lighter in weight and with a shorter nap.